Tesla Coil FAQs

Frequently Asked Questions About the Tesla Coil


Q:  How does a Tesla Coil work?

A:  A detailed explanation of how a Tesla Coil produces arcs and music can be found here.


Q:  Can SemiAxis customize a Tesla Coil for an exhibit?

A:  Yes.  While we have a standard design ready to build, we are also happy to develop and assemble any Tesla Coil to fit your needs.  As consultants and seasoned engineers we are here to work with you and help solve your problems.


Q:  How much does a SemiAxis Tesla Coil Cost?

A:  The standard design costs $7,500, giving the user an arc out to 12″ with a musical instrument interface.  All coils that SemiAxis builds are going to be in this price range, roughly $5,000 to $15,000.


Q:  Do you have Tesla Coils ready to ship?

A:  SemiAxis does not keep Tesla Coils in stock and the typical lead time is between one and two months.


Q:  How big is a Tesla Coil?

A:  Practical designs are typically between one and three feet tall and one to two feet across, though for the true Tesla Coil enthusiast, the sky is the limit.  Additional height can come from mounting the Tesla Coil onto the driving electronics.  Despite these fairly small dimensions, the effective range of Tesla Coil is much larger, being able to induce currents 10 or 20 feet away, requiring either a metal cage or a large inaccessible area around the coil during operation.


Q:  How much power does a Tesla Coil require?

A:  Power consumption varies by the arc length and operation mode.  The 12″ range easily runs on a typical 120V outlet consuming no more than a kilo-Watt, but as a system reaches out to 24″ it becomes increasingly necessary to run the Tesla Coil on a 240V system, consuming multiple kilo-Watts of power.


Q:  How safe is a Tesla Coil?

A:  Tesla Coils present several significant risks to operators and audience members that can all be mitigated fairly easily with good design and good practices.  The first problem a Tesla Coil presents are the very high voltages it generates, which can be dangerous if touched.  Tesla Coils also can induce currents in nearby electronic devices simply by proximity, potentially damaging them.  There is also the risks of fire that any high power electrical equipment presents.  To address these risks, SemiAxis Tesla Coils have built-in sensors and intelligence to shut the system down in the event of high temperatures and over currents in critical components.  Emergency-stop buttons are always included and easy to operate.  Each system requires the use of a key to power up and the activation of two separate switches to enable.  It is also highly recommended to either block access to within roughly 10 feet of a Tesla Coil or to enclose it in a conductive cage, both of which will prevent on-lookers from inadvertently interacting with the local electric field or touching the high-voltage components.


Q:  How will a Tesla Coil interfere with electronic devices?

A:  Tesla Coils in general produce two phenomena which can interfere with nearby electronics:  local electric fields and radiated emissions.  Radiated emissions are primarily a byproduct of the arc and are unfortunately difficult to attenuate.  This will most likely present itself as noise in near-by radios as far as several hundred feet away.  Near-field effects, however, are always present when the Tesla Coil resonates with or without an arc.  A Tesla Coil’s ability to wirelessly turn on a florescent light is a result of this phenomenon, but this is not only restricted to lights.  The Tesla Coil will energize anything conductive around it through capacitive coupling, potentially damaging sensitive electronics.  This can be completely mitigated through the use of a conductive cage so that the coil couples to the cage rather than the environment.  Near-field effects also taper off to ineffective levels around 10 feet away from the coil, so simple distance is also a very effective strategy for ensuring the safety of surrounding electronics.


Q:  What ways can we interact with a Tesla Coil?

A:  SemiAxis Tesla Coils can be operated manually by the included remote controller, or by any analog electronic or MIDI musical instrument.  This includes keyboards, electric guitars, and the SemiAxis digital Theremin.